The application of media lines of this type is particularly useful in motor vehicle applications with media that tend to freeze even at relatively high ambient temperatures because of their freezing point which can affect certain functions. This, for example, is the case with water lines used in windshield washer systems and particularly in lines used for conveying an aqueous urea solution, which is used as a nitrogen oxide (NOX) reduction additive for diesel motors with so-called SCR-catalytic converters. The electrical heating means can therefore be activated at low temperatures to prevent freezing or to melt the already frozen media.
Such a media line is described in WO 2007/073286 A1. For this purpose, an encapsulated connector is provided in a transitional area between the fluid connector, which is designed as a connector component of a fluid connector means, and the fluid hose, the encapsulated connector being disposed between the fluid connector and one end of a protective sheath that encloses the fluid line. A hollow area is disposed between the line and the encapsulated connector that also serves to house the electrical connections of the heating means. The connections are loosely placed in this hollow area, providing only inadequate protection against mechanical and other loads. A loose and undefined arrangement could cause the electrical connections to come into contact with one another and possibly cause a short circuit. The manufacture and installation of the known media line is furthermore difficult.
The underlying object of the present invention is to develop a heatable media line of the described type in such a manner that it can be manufactured using simple means while providing a high degree of process reliability and guaranteeing durable and secure performance characteristics.
According to the present invention, it is intended that the fluid line and/or the fluid connector within an arbitrary area, including the electrical connections of the heating means, are enclosed (over-molded or molded) by a plastic molding compound, particularly a thermo-plastic molding compound, for example on PA-basis. This will ensure that the necessary electrical connections are firmly bonded imbedded in a formed attachment component and are thus immovably fixed and protected against mechanical and other influences as well as electrically insulated against one another. The forming of the attachment component is preferably accomplished within a transitional area of the line end and fluid connector. This allows the advantageous development of a molded unit, which is comprised of the fluid line and at least one fluid connector connected to a line end and its heating means.
According to the present invention, a simple and reliable manufacturability can be achieved by first connecting a line end of the fluid line to the fluid connector and subsequently establishing the electrical connections between the heating media and, if applicable, the external supply leads and, finally, preferably over-molding a transitional area between the fluid connector and the fluid line including the electrical connections with a plastic compound. It is additionally or alternatively possible to (only) over-mold the fluid line with a plastic compound in an arbitrary, for example, approximately central section of its overall length while integrating the electrical connections of the heating media. A separate junction housing, which encloses the area of the formed plastic component, is then preferably installed in this area, the electrical supply leads being guided outward via a separate junction.
Additional preferred embodiment characteristics of the invention are included in the attached claims and the subsequent description.
The same reference numerals are used to identify identical components in the different diagrams of the illustrations.